Is 52C a physical limit?

Yes. The compressor can't pump more heat outside since it's already hot from working and trying to pump out the extracted heat as well.

For T1 class of devices, that 41 degrees is also a physical limit, not an artificial cut, because of their design.

You know, thermodynamics.

	▲	RandomLensman 3 hours ago \| parent [-]
		Why would the limit of T1 devices matter when there are ones that already can do hotter? Thermodynamics make things harder to remove heat but not sure how they forbid it (you need the hot side to be hotter than outside to pump heat). Might need stages, for example. We can cool things 200K and more below ambient.